1. Field of the Invention
The present invention relates to a power breaker, and more specifically to a power breaking including a rated current path and a power current path.
2. Discussion of Background
Laid-open specification DE 42 00 896 A1 discloses a power breaker which has a quenching chamber with two stationary consumable contacts which are at a distance from one another. The quenching chamber is filled with an insulating gas, preferably SF.sub.6 gas under pressure. When the quenching chamber is in the connected state, the two consumable contacts are electrically conductively connected to one another by means of a moving bridging contact. The bridging contact concentrically surrounds the consumable contacts, which are of cylindrical design. The bridging contact and the two consumable contacts form a power current path, on which current acts only during disconnection. During disconnection, the bridging contact slides down from a first of the consumable contacts and draws an arc which initially burns between the first consumable contact and the end of the bridging contact facing it. As soon as this end reaches the second consumable contact, the arc base commutates from the end of the bridging contact onto the second consumable contact. The arc now burns between the two consumable contacts and is blown until the arc is quenched. The pressurized insulating gas which is required for blowing is, as a rule, produced by means of a blowout piston which is connected to the moving bridging contact.
In addition, this power breaker has a rated current path in parallel with the power current path, which rated current path carries the operational current when the power breaker is switched on. The rated current path is arranged concentrically around the power current path. The bridging contact is in this case mechanically rigidly connected to a moving rated current contact which is arranged in the rated current path. During disconnection, the rated current path is interrupted first, and the current to be interrupted then commutates onto the power current path where, as described above, an arc is then struck and is then quenched.
Because of its dimensions, the bridging contact has a comparatively large mass to be moved, which must be accelerated and braked during switching processes. The power breaker drive has to provide the power required for this purpose.
Laid-open specification DE 31 27 962 A1 discloses a further power breaker which has a quenching chamber with two stationary consumable contacts at a distance from one another. The quenching chamber is filled with an insulating gas, preferably SF.sub.6 gas under pressure. When the quenching chamber is in the connected state, the two consumable contacts are electrically conductively connected to one another by means of a moving bridging contact. The bridging contact concentrically surrounds the consumable contacts, which are of cylindrical design. The bridging contact is in this case at the same time designed as a rated current contact. The disconnection process of this power breaker is similar to that for the power breaker described above.
Because of its dimensions, this bridging contact likewise has a comparatively large mass to be moved, which must be accelerated and braked during switching processes. The power breaker drive must provide the power required for this purpose.